Process for drying sand molds.



l. B. WALKER.

PROCESS FOR DRYING SAND MOLDS;

APPLICATION FILED Aus.4. 1911.

1,299,522, Patented Apr; 8,1919.

.To. all whom. it may concern:

JOHN B. WALKER, F BIRMINGHAM, ALABAMA.

PROCESS FOR DRYING SAND MOLDS.

Specification of Letters Patent.

Patented A t. 8, 1919.

Application filed August 4, 1917; Serial No. 184,468.

'Be it known that I, JOHN B. WALKER, a citizen of the United States of America, residing at Birmingham, in the county of J efferson and State of Alabama, have invented certain new and useful Improvements in Processes for Drying Sand Molds, of which the following is a specification.

My present invention relates to a process .for drying or baking the sand molds ofthe type used for casting large hollow articles such as ingot molds, heavy pipe and the like and in which a sand cheek and core areprovided.

The principles underlying my invention will be understood by a description thereof as applied to the baking of sand molds in which ingot molds are cast, such molds com= prising a flask having a sand cheek formed therein, a core arbor having a sand core formed thereabout, and a stool drag upon which the flask and arbor are mounted. Such an arrangement is generally described in my Letters Patent of the United States, No. 1,151,229, issued to me August 24th, 1915, by reference to which it will be seen that my preferred manner of ra-mmingthe cheek and core is by means of a jolt machine.

or jarring table which forms both cheek and core simultaneously, though my present invention is not concerned with the manner in which th sand is rammed to form-the cheek and core but rather with the manner in' which the flask and core are handled in order to dry or bake the sand. Heretofore the practice has been to provide an oven in which the cheek and core were baked in accordance with the practice well understood in this art. Such ovens are costly toconstruct and the niamtenance and heating of the oven, the careful handling necessary for the cheekandcore, and the warping of the flask and core arbor resulting from the oven heat all constitute. a considerable'part of the production cost of the castings.

p The object of my present invention is to devise a process by means of which the core and cheek can be bakedat a minimum expense and without requiring the construction or maintenance of a baking oven, thereby o permitting the drying process to take place at such point as is convenient in the foundry and without appreciable expense for labor, maintenance or equipment, and without delay in closing the mold after the cheek and core arev baked.

According to my process, the cheek and core after the rammingoperation and after being stripped from the pattern, are reassembled .so' that the mold cavity formed therein will constitute a flue having a bottom air inlet through which a gas coil or pipe is passed preferably conforming in shape'to the cross section of the mold cavity and designed to cause heated gases to flow up through the flue as formed between the core and cheek sand and to effectually dry the mold. Preferably the hot gases are producedby the combustion of gasat the base of the flue, the pipe serving in this instance as a burner,but obviously hot gas or air may be introduced from any suitable source where such an arrangement is more economical.

As illustrative of an apparatus for carrying my process into effect, reference is made to the accompanying drawings, in which Figure 1 presents a cross-sectional view taken on the horizontal plane 11through sand core 3. A flask 4: is shown formed in vertical half section's but its particular construction is not material except that provision should be made for connecting to its bottom edge 5'by a clamp 6 a stripping plate 7 which is adapted to be lifted off of the stool drag with the flask when the check is stripped from the pattern. The sand forming the check 8 is supported beneath by the stripping plate when the flask is lifted clear of the stool drag." Assuming that the core and cheek have been rammed about the pattern in any desired manner and both. core and cheek stripped from the pattern, we are now ready to proceed with the steps incident to the practice of my baking-process, accord ing to which the flask with 'the contained cheek is lowered back over the core and seated upon blocks 9 which support the flask sufiiciently above the stool to ermit the free. access of air to the bottom 0 the mold cavity and alsothe introduction of a gas pipe 10. This pipe '10 preferably is bent to a shape corresponding substantially with the 

